Method and apparatus for metal positioning and forming

ABSTRACT

A duct making apparatus includes a first station configured to accept a formable sheet material and a second station configured to receive the formable sheet material from the first station. The first station includes a mechanism for forming one of a male lock bend and a female lock seam in a leading edge of the formable sheet material. The second station includes a retractable conveyor. Movement of the sheet material from the first station to the second station defines an axis of travel of the sheet material. The retractable conveyor is selectively movable from a first position in which the retractable conveyor is in close association with the first station, and a second position in which the retractable conveyor is spaced from the first station.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional application which claims the benefit ofU.S. application Ser. No. 14/163,038 filed on Jan. 24, 2014, whichfurther claims the benefit of U.S. Provisional Application Ser. No.61/756,226, filed on Jan. 24, 2013, and U.S. Provisional ApplicationSer. No. 61/766,207, filed on Feb. 19, 2013, which are hereinincorporated by reference in their entireties.

FIELD OF THE INVENTION

The present invention relates generally to metal working apparatuses andmethods, and more particularly, to an apparatus and method for bendingsheet metal to form ventilation ducts.

BACKGROUND OF THE INVENTION

Box-shaped ducts are extensively used in heating and ventilating systemsto distribute heated or cooled air throughout a structure. The ducts arecommonly formed in sections of predetermined length, which are thenconnected to form a continuous air distribution duct. The material fromwhich the duct sections are formed is sheet metal of the desired gaugefed from a roll or coil of material. As the sheet metal uncoils, it isflattened or straightened to remove the curved set in the material thatexists from it being coiled. The sheet metal is then notched along itsside edges at predetermined distances where the corners of the ductsection will be formed. A shear then cuts the material into blanks of alength necessary to form a finished duct section. This notched blank isthen moved 90 degrees onto a roll former to form the male and femaleportions of a lock seam at the opposite ends of the blank. The blank isthen transferred once again, usually 90 degrees, into a roll former toform the flanges that will provide for connection of the individual ductsections. When the flanges have been formed, the blank is thentransferred to a sheet metal break where three 90 degree bends are madeto form the box-shaped duct section.

As will be readily appreciated, transferring the material bothlongitudinally and sideways from station to station to form the lockseams and flanges requires a considerable amount of floor space for theequipment, conveyors and transfer tables between the stations. Oftentimes, therefore, large spaces are needed to accommodate the width ofexisting duct fabricating machines, which increases overhead operatingcosts.

There is therefore a need for an improved method and apparatus forforming duct sections which minimizes the amount of floor space requiredto carry out the complete forming process, and which provides for theforming of duct sections more quickly and efficiently and at a lowercost as compared to existing apparatuses.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an automatic ductmaking apparatus for metal positioning and forming.

It is an object of the present invention to provide a duct makingapparatus for bending sheet metal to form ventilation ducts.

It is another object of the present invention to provide a duct makingapparatus that is smaller and fits into existing shop areas that are toosmall for existing duct forming machinery.

It is another object of the present invention to provide a duct makingapparatus that is capable of providing various styles of ducting,including welded flange and raw edge connections using slide on flangetechnology.

It is another object of the present invention to provide a duct makingapparatus that is narrow in width as compared to existing systems.

It is another object of the present invention to provide a duct makingapparatus that competes with existing wide-footprint systems.

It is another object of the present invention to provide a duct makingapparatus that is configured to move a duct blank workpiece straightforward during forming operations without moving the duct blank sidewaysor reversing the duct blank in the opposite direction for completing theoperations for finishing the duct section.

It is another object of the present invention to provide a duct makingapparatus that substantially eliminates the use of servomotors forpositioning of the duct blank during forming operations.

According to an embodiment of the present invention, a duct makingapparatus includes a first station configured to accept a formable sheetmaterial and a second station configured to receive the formable sheetmaterial from the first station. The first station includes a mechanismfor forming one of a male lock bend and a female lock seam in a leadingedge of the formable sheet material. The second station includes aretractable conveyor. Movement of the sheet material from the firststation to the second station defines an axis of travel of the sheetmaterial. The retractable conveyor is selectively movable from a firstposition in which the retractable conveyor is in close association withthe first station, and a second position in which the retractableconveyor is spaced from the first station.

According to another embodiment of the present invention, a duct makingapparatus is provided. The duct making apparatus includes a firststation configured to accept a formable sheet material, a second stationconfigured to receive the formable sheet material from the firststation, and a third station including a roll forming assembly. Thesecond station includes a conveyor for moving the sheet material alongan axis of travel. The roll forming assembly is selectively movable intoand out of a space between the first station and the second station in adirection orthogonal to the axis of travel.

According to yet another embodiment of the present invention, a methodof forming a duct section from a web of material is provided. The methodincludes the steps of, at a first station, forming one of a male lockbend and a female lock seam in a leading edge of the web of material, ata second station, receiving the web of material from the first station,and at a third station, forming the other of a male lock bend and afemale lock seam in a trailing edge of the web of material.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be better understood from reading thefollowing description of non-limiting embodiments, with reference to theattached drawings, wherein below:

FIG. 1 is a schematic plan view of a prior art U-shaped duct makingapparatus.

FIG. 2 is a schematic plan view of another prior art U-shaped ductmaking apparatus.

FIG. 3 is a schematic plan view of a prior art Z-shaped duct makingapparatus.

FIG. 4 is a schematic plan view of another prior art Z-shaped ductmaking apparatus.

FIG. 5 is a top plan view of an apparatus for metal positioning andforming according to an embodiment of the present invention.

FIG. 6 is a side elevational view of the apparatus of FIG. 5.

FIG. 7 is side elevational view of a positioning stop of the apparatusof FIG. 5, illustrated in its raised, pass through position.

FIG. 8 is a side elevational view of the positioning stop of FIG. 7,illustrating the positioning stop in a lowered, engaging position with asheet held in a slightly reversed position.

FIG. 9 is a side elevational view of a conveyor and holding clamp of theapparatus of FIG. 5, illustrating the holding clamp in a raised,pass-through position.

FIG. 10 is a side elevational view of the conveyor and holding clamp ofFIG. 9, illustrating the holding clamp in a lowered, clamping position.

FIG. 11 is a side elevational view of a lock seam roll forming device ofthe apparatus of FIG. 5, showing the positing stop of FIG. 7 in itsraised, pass-through position.

FIG. 12 is a side elevational, expanded view of the conveyor with theretractable conveyor portion in its extended position ready forreceiving a sheet as it exits the shear.

FIG. 13 is another top, plan view of the metal positioning and formingapparatus of FIG. 5, showing a more detailed illustration thereof.

FIG. 14 is a side elevational view of the metal positioning a formingapparatus of FIG. 5, showing a more detailed illustration thereof andshowing the retractable conveyor in an extended position.

FIG. 15 is a side elevational view of the metal positioning a formingapparatus of FIG. 5, showing a more detailed illustration thereof andshowing the retractable conveyor in a retracted position.

FIG. 16 is a side elevational view of the metal positioning a formingapparatus of FIG. 5, showing a more detailed illustration thereof andshowing the positioning of the roll forming assembly.

FIG. 17 is an end view of a duct section manufactured utilizing theapparatus of FIG. 5, with both lock seams and bends that complete arectangular duct section.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIGS. 1-4 are schematic views of known automatic duct making systems 10,20, 30, 40 for making completed duct sections. Each of these systems 10,20, 30, 40 include a start end 12, a lock seam roll forming section 14and a finish end 16. As shown therein, with each of these systems 10,20, 30, 40, sheet metal is unwound from large rolls or coils 18. As iswell known to those skilled in the art, the width of the coil 18determines the length of the completed duct section.

A duct blank is cut from the coil 18 and advanced in a first direction,e.g., from right to left as shown in FIGS. 1-4. The duct blank is thenmoved in a second direction substantially perpendicular to the firstdirection (e.g. from top to bottom or bottom to top as shown in FIGS.1-4) and passes through the roll forming section 14. The roll formingsection 14 has roll forming stations that are oriented perpendicular tothe first direction of movement and form male and female lock seams,respectively, on opposed edges of the duct blank as the duct blankpasses therethrough. The duct blank is then advanced in a thirddirection generally parallel to the first direction for subsequentbending and finishing operations prior to arriving at the finish end 16as a substantially completed duct section.

As will be readily appreciated, the duct blank must be moved in adirection substantially perpendicular to the initial, first direction ofmovement in order to pass through the roll forming stations of the rollforming section 14 to form the male and female lock seams. As a result,prior art duct making apparatus typically take a U-shaped configuration,as illustrated by the duct making apparatuses 10, 20 shown in FIGS. 1and 2, or a Z-shaped configuration, as illustrated by the duct makingapparatuses shown in FIGS. 3 and 4. Both the U-shaped and Z-shapedapparatuses, however, require a considerable amount of floor space dueto the need to move the duct blank perpendicularly through the rollforming section 14 and, therefore, are often substantially wider thanwill fit into many duct manufacturing shops. Indeed, the apparatuses 10,20, 30, 40 shown in FIGS. 1-4 are approximately 25 feet wide, therebyrequiring a large space to accommodate such apparatuses.

Turning now to FIGS. 5 and 6, an embodiment of a metal positioning andforming apparatus 100 of the present invention addresses the issue oflimited floor space in many duct manufacturing shops, among others, byproviding a substantially linear path of travel of the duct blankthroughout the apparatus 100, even through the roll forming section thatforms the male and female lock seams.

As shown therein, the metal positioning and forming apparatus 100includes, at least, a start end 110, a first station 112, a secondstation 114, a third station 116, and a finish end 118 disposed about acommon axis. At the start end 110 sheet metal of a desired gauge andwidth is supplied in large rolls or coils 120. As is well known to thoseskilled in the art, the sheet metal material from one of the coils 120is fed by a feeder (not shown) into the first station 112. The firststation includes a coil straightener 122, a notching section 124 and abending shear 126, which each may take one of various forms known in theart.

The coil straightener 122 contains a plurality of rolls that will removethe set in the material caused by it being wound on a coil 120. The coilstraightener 122 thus straightens the material and feeds the web ofmaterial to the notching section 124 that provides corner notches, ifneeded, for the style of duct section being processed. The notchingsection 124 is programed to notch the side edges of the web of materialat predetermined distances where the material will ultimately be bent toform the box-shaped duct section. In other words, the distance betweenthe notches will correspond to the dimensions of the finished ductsection.

The web of material then moves forward, from right to left in FIGS. 5and 6, into the bending shear 126 of the first station 112. The bendingshear 126 bends the leading edge of the web of material utilizing abuilt in bending die assembly to form a male lock seam, and thenproceeds to shear the web of material to make a generally rectangularduct blank flat pattern. Movement of the web of material along thepathway defined by the apparatus 100, from starting end 110 to finishend 118 defines an axis of travel of the web.

With further reference to FIGS. 5 and 6, the second station 114 ispositioned in line with the first station 112 along a linear directionof travel of the duct blank (i.e., the axis of travel) and includes aretractable conveyor 128, a feed conveyor 130 and a stop and clampassembly 132. As best shown in FIG. 7, the stop and clamp assembly 132includes a vertically movable clamp 134 and a pivotable stop 136. Theclamp 134 and stop 136 may be hydraulic, pneumatic or electricallyactuated, although any other means for actuating the clamp 134 and stop136 along their constrained paths of travel known in the art may also beutilized without departing from the broader aspects of the presentinvention.

The stop 136 is selectively rotatable between a raised, pass-throughposition, as illustrated in FIG. 7, and a lowered, engaging position, asillustrated in FIG. 8, as discussed in detail below. Likewise, the clamp134 is selectively movable between a, raised position in which the clamp134 is spaced from a duct blank carried on the retractable conveyor 128,as shown in FIG. 9, and a lowered, clamping position in which the clamp134 contacts the duct blank and holds it against the retractableconveyor 128, as also discussed in detail below.

Importantly, the retractable conveyor 128 of the second station 114 islinearly movable in the direction of arrow A, as shown in FIG. 12. Inparticular, the retractable conveyor 128 is linearly movable between afirst position in close association with the first station 112, as shownin FIG. 15, and a second position in which the retractable conveyor 128is spaced from the first station 112, as shown in FIG. 16.

In operation, as the male lock seam is formed in the leading edge of theduct blank and the duct blank is separated from the web of material, theretractable conveyor 128 is advanced against the direction of travel ofthe metal web to the extended position shown in FIG. 15. At the sametime, the clamp 134 and stop 136 are moved to their retracted,pass-through positions which allows the duct blank to be advanceddownstream. In this position, the retractable conveyor 128 supports theweb while it is fed forward and cut to proper length by the bendingshear 126, and prevents the web from bowing or hanging down, which couldcause jamming. The retractable conveyor 128 remains in this extendedposition until the duct blank passes the stop and clamp assembly 132, atwhich time the conveyor 128 retracts and is positioned for a subsequentroll forming operation, as discussed hereinafter.

In particular, once the trailing edge of the duct blank passes the stop136, the stop rotates downward to its engaging position, as illustratedin FIG. 8. The conveyor 128 then again reverses direction, moving theduct blank upstream, until the trailing edge of the duct blank contactsstop 136. At this position, clamp 134 is moved into clamping position,shown in FIG. 10, to clamp the duct blank against the retractableconveyor 128. Once the duct blank is clamped in proper position, stop136 again rotates to its retracted, pass-through position shown in FIG.7. While the figures of the present invention illustrate the utilizationof a single clamp 134 and single stop 136, more than one clamp 134 andstop 136 may be utilized to provide additional clamping and alignment,respectively, without departing from the broader aspects of the presentinvention.

With reference to FIGS. 11-13 and 16, the third station 116 includes afemale lock seam roll former 140 having a plurality of die pairs. In thepreferred embodiment, the roll former 140 may generally take the form ofany roll former commonly known in the art that is utilized to formvarious style lock seams. In particular, the roll former 140 may beconfigured to form any style of lockseam, such as a Pittsburg seam orSnaplock seam, on the trailing edge of the duct blank, as discussedbelow. Importantly, the roll former 140 is mounted on a laterallytraversing frame 142 that is positioned between the first station 112and second station 114.

Once the duct blank is clamped in position by the clamp 134, andconveyor 128 is spaced from the first station 112, roll former 140 ofthe third station 116 moves in a direction substantially perpendicularto the axis of travel of the duct blank and engages the trailing edge ofthe duct blank. The roll former 140 travels across the trailing edge ofthe duct blank, perpendicular to the linear direction of travel of theduct blank, thereby forming a female lock seam. Traversing the rollforming head 140 may be accomplished via hydraulic, pneumatic orelectrical means, although any other means known in the art may also beutilized without departing from the broader aspects of the presentinvention. As discussed in detail below, it is an important aspect ofthe present invention that the roll former head 140 is selectivelymovable orthogonal to the axis of travel of the web of material throughthe apparatus 100.

After forming the female lock seam in the trailing edge of the ductblank, the clamps 134 are released and the duct blank is moved linearlydown the second station 114 by stationary feed conveyor 130 foradditional operations. In particular, once seaming is complete, theconveyor 128 retracts (moves to the left in FIG. 12) and clamp 134raises to its pass-through position, allowing the duct blank to proceeddownstream through the system reaching feed conveyor 130. Once the trailedge of the duct blank is fully on conveyor 130, the roll former 140 isreversed and moves to its original starting position on one side of theapparatus 100. The retractable conveyor 128 is then extended to itsstarting position adjacent to the first station 112 such that theprocess can be repeated for another duct section.

As alluded to above, additional operations may be carried out downstreamafter formation of the male and female lock seams. In an embodiment, theduct blank may proceed forward through the system, reaching feedconveyor 130, transverse connection/transverse flange roll former 144,brake feed conveyor 146, bending brake 148 and finally exiting endconveyor 150, thus competing a fully automatic cycle generating acompleted duct section. These subsequent operations may be anyoperations known in the art of duct section formation, including, butnot limited to, the formation of flanges on the ends of the duct sectionand bending of the duct section to form an enclosed duct.

In particular, the transverse connection roll former 144 may take anyform known in the art for forming any type of transverse flange known inthe art. Moreover, the apparatus 100 of the present invention is capableof providing all styles of ducting including welded flange and raw edgeconnections using slide on flange technology in a fully automaticmanner. As will be readily appreciated, the automatic duct makingapparatus 100 of the present invention is capable of making any style ofducting by adding any downstream bending/forming stations necessary toachieve the desired style.

In an embodiment, the apparatus 100 may include a computer orprogrammable logic controller (not shown) and a plurality of switches,sensors and timers that operate in conjunction with one another andaccording to a set of instructions stored in memory. In particular, allof the operational sequences for forming a completed duct section may becarried out automatically under the control of the computer orprogrammable logic controller in concert with the switches, sensors andtimers.

With further reference to FIGS. 13-16, in an embodiment, the apparatus100 may include locating pins 152 as an alternative means of properlypositioning the duct blank on the conveyor 128 for the subsequent femalelock seam forming operation. As shown therein, the locating pins 152 arepivotally mounted to the second station 114. During operation, theconveyor 128 retracts to a position that allows the locating pins topivot downward. Once in the down position, the conveyor 128 is reversedto transport the duct blank upstream until the locating pins 152 arecontacted. In an embodiment, the pins 152 themselves can be used tocomplete a circuit confirming that the trailing edge of the duct blankis in correct position. Other sensing means known in the art may also beutilized without departing from the broader aspects of the presentinvention. Once the duct blank is confirmed to be in the properposition, holding clamps 134 are extended to clamp the duct blank to theconveyor frame. The holding clamps 134 hold the duct blank in properposition during retracting of the locating pins 152 during the rollforming operation, as discussed above.

A completed duct section 200 produced by the duct making apparatus 100of the present invention is shown in FIG. 17. As shown therein thecompleted duct section has a male lock seam 210 formed by the bendingshear 126, a female lock seam 212 formed by the transversely movableroll former 140, and a plurality of bends 214 that complete therectangular duct section. The transverse end connections formed bytransverse connection roll former 144 are omitted in FIG. 17.

As will be readily appreciated, by mounting the roll former 140 on alaterally movable frame 142, the roll former 140 is able to moveorthogonally across the trailing edge of the stationary duct blank toform the female lock bend. This is in contrast to existing systems whichtypically put the duct blank in motion and move the blank laterally(i.e., orthogonal to the initial direction of travel) through astationary roll-forming device to form both the male and female lockseams. As the need to move the duct blank sideways is obviated by theprovision of the transversely movable roll former 140, all of thestations of the apparatus 100 of the present invention may be alignedlinearly, as opposed to in a “U” or “Z” configuration as has beenheretofore required in the art. With this linear arrangement ofstations, the sheet material and the duct blank cut therefrom can be fedentirely linearly throughout the entire apparatus 100, from start end110 to finish end 118.

As a result of this configuration, the apparatus 100 of the presentinvention is much narrower as compared to existing duct makingapparatuses configured to handle the same size sheet material. Inparticular, in an embodiment, the duct making apparatus 100 of thepresent invention may be approximately half of the width of prior artcomplete duct fabrication systems. As will be readily appreciated,because of this smaller and narrower footprint, the apparatus 100 may beutilized in smaller shops, thereby allowing such smaller shops tocompete with larger shops utilizing the wider, existing duct makingsystems by controlling costs and quality.

With existing systems, there is a need to move various sizes and gaugesof sheet material through side motions to form the lock seams, whichtypically requires a variety of guiding and setting requirements to movethe sheets squarely and accurately without jams, run off conditions orbuckling difficulties. With the apparatus 100 of the present invention,however, these problems are eliminated because the sheet material/ductblank moves in a straight line from start to finish, allowing simpleconveyance.

In addition to the above, the apparatus 100 of the present inventionallows return to previous, more friendly notching and seaming incustomary methods allowing minimal openings at the corners of the ductsections. This is desirable for the mechanical contractors because itreduces costs required to treat unnecessary openings in the notchedcorner area. This is in contrast to many existing systems that form adrive cleat before shearing the duct blank to length and thensubsequently form the locks seams causing a substantial notch-backrequirement so the cleat isn't crushed during the seaming operation.

In the appended claims, the terms “including” and “in which” are used asthe plain-English equivalents of the respective terms “comprising” and“wherein.” Moreover, in the following claims, the terms “first,”“second,” “third,” “upper,” “lower,” “bottom,” “top,” “up,” “down,” etc.are used merely as labels, and are not intended to impose numerical orpositional requirements on their objects. Further, the limitations ofthe following claims are not written in means-plus-function format andare not intended to be interpreted based on 35 U.S.C. § 112, sixthparagraph, unless and until such claim limitations expressly use thephrase “means for” followed by a statement of function void of furtherstructure.

This written description uses examples to disclose several embodimentsof the invention, including the best mode, and also to enable any personskilled in the art to practice the embodiments of invention, includingmaking and using any devices or systems and performing any incorporatedmethods. The patentable scope of the invention is defined by the claims,and may include other examples that occur to those skilled in the art.Such other examples are intended to be within the scope of the claims ifthey have structural elements that do not differ from the literallanguage of the claims, or if they include equivalent structuralelements with insubstantial differences from the literal languages ofthe claims.

As used herein, an element or step recited in the singular and proceededwith the word “a” or “an” should be understood as not excluding pluralof said elements or steps, unless such exclusion is explicitly stated.Furthermore, references to “one embodiment” of the present invention arenot intended to be interpreted as excluding the existence of additionalembodiments that also incorporate the recited features. Moreover, unlessexplicitly stated to the contrary, embodiments “comprising,”“including,” or “having” an element or a plurality of elements having aparticular property may include additional such elements not having thatproperty.

Since certain changes may be made in the above-described duct makingapparatus, without departing from the spirit and scope of the inventionherein involved, it is intended that all of the subject matter of theabove description or shown in the accompanying drawings shall beinterpreted merely as examples illustrating the inventive concept hereinand shall not be construed as limiting the invention.

What is claimed is:
 1. A method of forming a duct section from a web of material, said method comprising the steps of: at a first station, forming one of a male lock bend and a female lock seam in a leading edge of said web of material; at a second station, receiving said web of material from said first station; said second station comprising a conveyor which is selectively movable from a first position in which said conveyor is in close association with said first station, and a second position in which said conveyor is spaced from said first station, and; at a third station having a roll forming assembly, forming the other of a male lock bend and a female lock seam in a trailing edge of said web of material by engaging said roll forming assembly with said trailing edge of said web of material and moving said roll forming assembly in a direction orthogonal to an axis of travel of said web into a space formed between said first station and said second station when said conveyor is in said second position.
 2. The method according to claim 1, wherein: said step of receiving said web from said first station includes supporting said web on said conveyor and aligning said trailing edge of said web with said roll forming assembly of said third station.
 3. The method according to claim 2, further comprising the step of: at said second station, clamping said web to said conveyor in alignment with said roll forming assembly such that said web remains stationary while said roll forming assembly forms said other of said male lock bend and said female lock seam.
 4. A method of forming a duct section from a web of material, said method comprising the steps of: at a first station, forming one of a male lock bend and a female lock seam in a leading edge of said web of material; at a second station, receiving said web of material from said first station; and; at a third station, forming the other of a male lock bend and a female lock seam in a trailing edge of said web of material; said step of receiving said web from said first station includes supporting said web on a conveyor and aligning said trailing edge of said web with a roll forming assembly of said third station; said roll forming assembly is configured to engage said trailing edge of said web; and wherein said step of forming the other of said male lock bend and said female lock seam includes moving said roll forming assembly into a space between said first station and said second station in a direction orthogonal to an axis of travel of said web; at said second station, clamping said web to said conveyor in alignment with said roll forming assembly such that said web remains stationary while said roll forming assembly forms said other of said male lock bend and said female lock seam; said conveyor is selectively movable from a first position in which said conveyor is in close association with said first station, and a second position in which said conveyor is spaced from said first station to allow passage of said roll forming assembly. 